Possible resolution 3:
After configuring access to the 3D X Server and booting to init 5, you should log off completely and log in for the VirtualGL test. I did not log-off and was wondering why I have the above error.

“VirtualGL is an open source package which gives any Unix or Linux remote display software the ability to run OpenGL applications with full 3D hardware acceleration…..With VirtualGL, the OpenGL commands and 3D data are instead redirected to a 3D graphics accelerator on the application server, and only the rendered 3D images are sent to the client machine……” For more information see What is VirtualGL? from Project Website"

Friday, July 23, 2010

glxgears is an OpenGL program that reports FPS (frames per second) numbers. I find this program useful to test out OpeGL Renderer such as simple comparison between VNC, VirtualGL and of course the Direct-From-The-Machine itself.

When you encounter CHECK_NRPE: Error - Could not complete SSL handshake ... If you encounter this error when using the nagios check_nrpe plugin and the monitored server, it could be due to the following issues.

You will have only an SSL problem if the SSL version used by the check_nrpe and the NRPE daemon are incompatible

Access permission for nrpe.cfg on the monitored server is blocking access. It should have read access rw_r__r__

Permission error within the /etc/nagios/nrpe.cfg file.

allowed_hosts=127.0.0.1,192.168.x.x

You will also receive the error if the Nagios Server cannot access the NRPE serice at all through the xinetd.d service. Check the /etc/xinetd.d/nrpe service

As System Administrator, how do we detect the Hyperthreading in Linux Server? Which CPU are physical and which is logical? For those running HPC, this could be important as you are more interested in number of physical CPU rather than Logical CPU count.

Installing Nagvis on Nagios 3.x is quite a challenge on CentOS 5.x. Still in the process of doing it. But I thought I record some of the notes during installation of Nagvis prerequisties.

Before you install the Nagvis prerequisties, do install the following:

1. Install mySQL database

# yum install mysql mysql-devel mysql-server gcc-c++

2. Install PHP and required PHP modules

# yum install php* php-gd php php-mbstring php-mysql

It is useful to install NDOutils as Nagios' NDOutils store all configuration and event data from Nagios into a database, which will help facilidate quicker retrieval and processing event data. Lots of other Nagios-related tools (e.g. NagVis rely on the MySQL backend made available by NDOUtils. Do refer to this excellent article NDOutils on CentOS

3. Compiling Nagvis on CentOS 5.x
Finally, here the unfinished portion, first go to Nagvis Download site
Untar the Nagvis package and install

Graph visualization is a way of representing structural information as diagrams of abstract graphs and networks. Automatic graph drawing has many important applications in software engineering, database and web design, networking, and in visual interfaces for many other domains.

To install GraphViz, download the correct repository according to the distribution of your choice. The supported distribution is Fedora, RHEL, Ubuntu, Windows, Mac

The easiest way to install and maintain graphviz on RHEL or Centos is to use yum. To set up yum, download the graphviz-rhel.repo file

Tuesday, July 13, 2010

"Learn how to install and use Eclipse specifically for Linux® running on IBM® POWER™ processor-based systems. Learn, also, how to use Eclipse to compile and run applications through sample Java™ and C programs."

"/usr/local/eclipse/configuration/org.eclipse.osgi. A common reason is that the file system or Runtime Environment does not support file locking for that location. Please choose a different location,or disable file locking passing "=Dosgi.lockling=none" as a VM argument. 'usr/local/eclipse/configuration/org.eclipse.orgi/.manager/.fileTableLock (Permission denied)"

To solve the issue, you simply have to initiate a flag "-configuration" and point the location to your home directory

Wednesday, July 7, 2010

I was trying to move albums by clicking "move album" link and the pop-up windows show nothing at least for Internet Explorer. there was no change of website name or any other configuration change. The first thing I did was to take a look at the log file at

Tuesday, July 6, 2010

Installing Fedora 13 on HP Mini Note 2140 is a breeze except that for the Broadcom 4312G 802.11b/g Wi-Fi Adapter will not be installed. To install the driver for Broadcom 4312G 802.11b/g Wi-Fi Adapter will not be installed, follow the excellent tutorial on Fedora Broadcom Linux STA Driver .

Saturday, July 3, 2010

Testdisk by CGSecurity is a useful toolkit to help. According to the TestDisk Website,

"TestDisk is a powerful free data recovery software! It was primarily designed to help recover lost partitions and/or make non-booting disks bootable again when these symptoms are caused by faulty software, certain types of viruses or human error (such as accidentally deleting a Partition Table). Partition table recovery using TestDisk is really easy."

"In addition, it can

Fix partition table, recover deleted partition

Recover FAT32 boot sector from its backup

Rebuild FAT12/FAT16/FAT32 boot sector

Fix FAT tables

Rebuild NTFS boot sector

Recover NTFS boot sector from its backup

Fix MFT using MFT mirror

Locate ext2/ext3 Backup SuperBlock

Undelete files from FAT, NTFS and ext2 filesystem

Copy files from deleted FAT, NTFS and ext2/ext3 partitions. "

Testdisk is very useful expecially if you are dual-booting from both Linux and Windows and if accidentally deletion. a few listed tutorial from a much larger list.